Important head/cylinder bolt question

I removed the head and cylinders on my xj650 Maxim yesterday and when I got the cylinders off there was these plastic-like sleaves that crumbled off of the bolts. I think they are supposed to be spacers to keep the cylinders on tight or something but I mreally concerned about it. Can I replace these? or is there some sort of alternative? Below are some pics.

 

They're replaceable. Len has them.

Edit: The oil transfer washers under the cap nuts on the far right side that Fitz is talking about are the only two copper washers of the lot.

 

What are they called?

 

I wiped mine off put some grease on them and slid on some heat shrink

 

They're called "cylinder head-to-crankcase black plastic, high-heat SHEATHING."

More important is that big cam chain gallery seal. If it's crispy/crunchy/crumbling, it needs to be replaced and no, it's not cheap.

Also be very aware of the o-rings that go around the dowel pins for the head bolts on the RH side. The RH outer head bolt passages are actually the oil feeds to the top end; the washers under those cap nuts are sealing washers that also need to be replaced.

 

I learned this the hard way, and try to remind people to replace 'em too. Good call

 

Can someone send me a link to some of those plastic heat sleeve things? Thanks!

 

I'd just get in contact with Len at info@xj4ever.com

Sure you could do an extensive search on yamahapartshouse.com and look up the part number yourself but Len is a trustworthy guy on this site

 

x1^. Len and xj4ever provide great service to this forum.

 

Do I need one of these for every bolt on the engine?

 

Len (username- chacal) will know, and he won't sell you more than you need anyway, seriously he's a great guy who's in it for the love of the bikes not to get rich & anyone who's had dealings with him I'm sure would 100% recommend him to you.

 

What is the purpose of the sheathing around the head bolts?

 

Noise reduction mainly.